The quadrupoles and dipoles of the Soleil synchrotron storage ring

The quadrupolar and dipolar magnets of the Soleil storage ring were studied for the detailed design study of the Soleil project in 1997-1998. There are two types of quadrupole, 128 short quadrupoles and 32 long quadrupoles with the same transverse magnetic section. The renewal of the Soleil detailed design study in 2001 updated the machine parameters, in particular its operating energy to a higher level (2.75 GeV).


The reworking of the Soleil detailed design study allowed to finalise the study of two types of quadrupole. Modelling carried out using the Tosca 3D code gave optimisation of the transverse section and of the end geometry of these magnets by minimising harmonic rates detrimental to the optics, at the same time as holding integral uniformity of field gradient in the useful zone at a level better than 5×10-4. Only the 45° end chamfer differs from one quadrupole to another so as to reduce the dodecapole and “20-pole” multipolar terms to values below 5×10-5. The quadrupole prototypes will be measured during 2004 at the Soleil magnetic measurement laboratory at the CEA/Orme des Merisiers site.

The storage ring dipole operates at a nominal induction of 1.71 T, corresponding to a machine energy of 2.75 GeV. The preliminary version of this dipole was curved with a C-type magnetic circuit. It is now of straight H-type allowing the 5×10-4 uniformity required of the field integrals to be reached, as well as a magnetic length which is adjusted to the curvilinear length of the iron.

The field uniformity of a dipole prototype measured in the magnetic measurement laboratory conforms to the simulations. Welds along the magnet to hold the plates in position have however caused a 1 mm misalignment of the magnetic lengths between input and output. Analysis of this shortcoming is ongoing.


#826 - Last update : 10/21 2005


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